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package uchicago.src.sim.gui;

import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
//import uchicago.src.sim.gui.Network2DDisplay;

/**
 * An Interface for laying out graphs (ie networks of nodes and edges). This
 * is used by Network2DDisplay as the source of nodes and edges to draw.
 * The intention here is that the layout algorithm is separated from the
 * actual drawing code. Concrete implementations should work with lists of
 * DrawableNonGridNodes. These nodes are expected to draw themselves, but
 * have their x and y coordinates set via whatever layout algorithm is
 * used by the implementing class.<p>
 *
 * GraphLayout extends ActionListener. The intent here is that
 * computationally intensive layouts can listen for the Controller's
 * stop, pause, etc. button clicks and interrupt themselves. See the source
 * code to KamadaGraphLayout for an example of this. 
 *
 * @author Nick Collier
 * @version $Revision: 1.6 $ $Date: 2004/11/03 19:50:59 $
 */
public interface GraphLayout extends ActionListener {

  /**
   * Gets the height of the area on which to layout the graph.
   */
  public int getHeight();

  /**
   * Gets the width of the area on which to layout the graph.
   */
  public int getWidth();

  /**
   * Sets the list of nodes to be laid out by this GraphLayout.
   */
  public void setList(List listOfNodes);

  /**
   * Appends a list of nodes to the current list of nodes to be laid
   * out by this GraphLayout.
   */
  public void appendToList(List listOfNodes);

  /**
   * Appends the specified nodes to the list of nodes to be laid out by
   * this GraphLayout.
   */
  public void appendToList(DrawableNonGridNode node);

  /**
   * Updates the layout of this graph by setting the x, y coordinate of
   * each DrawableNonGridNode in the current list of nodes.
   */
  public void updateLayout();

  /**
   * Gets the list of nodes.
   */
  public ArrayList getNodeList();

  /**
   * Sets whether the display will update or not when updateLayout is
   * called. This allows for the regular scheduling of updateLayout
   * together with the ability to skip the actual execution of the method.
   *
   * @param doUpdate if true, this GraphLayout will perform the layout when
   * updateLayout is called. If false, then the layout will not be
   * performed.
   */
  public void setUpdate(boolean doUpdate);
}
